Posted: 14/03/2017 at 15:37
The problem with any insecticide or washing up liquid solution is that it is indiscriminate and kills beneficial insects too. If you can, just squish the majority of them with your fingers and squirt the rest with a hosepipe.
I found, in my last garden, that if I fed the birds all year round the sparrow and tits would hoover up aphids to feed to their young chicks - essential source of moisture till hey can fly the nest and drink - and then ladybirds and hoverfly would arrive and take care of the rest. No sprays.
Just need to be patient while nature gets the balance of predator and prey sorted and, if you can, keep your plants well ventilated and separated to reduce infestations in confined spaces.